Like space, the past is always nearer than we think. As a boy, I knew a woman who once cut Thomas Hardy’s hair. For his part, Hardy knew an old countryman who had set eyes on Napoleon when the Bellerophon put into Plymouth Sound, en route to St Helena. The Napoleonic Wars are just three human lifetimes away and if you get to my age you will know that a lifetime is no vast span. Anthropologists have a thing called the ‘long generation’ – the era extending from the birth of one person to the death of the latest-born person that he or she could have met. This is where it gets hair-raising. As James Hawes puts it, in the foreword to his exhilarating The Shortest History of England (2021), ‘Seven long generations . . . the old and the young holding hands – and we are back at the Battle of Hastings.’ This inspires the same sort of vertigo as the knowledge that standing in central London you are nearer to outer space than you are to, say, Market Harborough.